3d image convertible projection optical system

ABSTRACT

A 3D image convertible projection system for viewing a 3D broadcasting and 3D DVD image, using a general projector that receives a left-eye image and a right-eye image for a 3D image in one frame and projects them toward a projection lens, wherein the left-eye image and the right-eye image in 2D form are magnified so that a vertical magnification rate is 0 and a horizontal magnification rate is 1.5-2.5 times. At the same time the left and right images are divided leftward and rightward through an optical system consisting of first and second curved surface mirrors, and then the images are secondly reflected and magnified to be projected toward a screen. The 3D image can then be viewed using polarization eyeglasses through image division, image horizontal magnification rate, and overlapping projection on a polarization separation screen.

CROSS-REFERENCE(S) TO RELATED APPLICATION

This application claims priority of Korean Patent Application No., filed on, in the Korean Intellectual Property Office, which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a 3D image convertible projection optical system to which a 2D projector without having a 3D image function is connected and in which a left-eye image and a right eye-image for a 3D image are magnified, divided, polarized and projected on a general screen, and thereby viewing the 3D image on the screen.

2. Description of the Related Art

Currently, a 3D image DVD has been in a market and a 3D image broadcasting for a sports game such as a soccer game, etc., has been started.

This 3D image for the 3D image broadcasting has been transmitted as one image by reducing a left-eye image 101 and a right eye-image 102 to a half of them with respect to a left and right side or a top and bottom side in one frame 103.

That is, as in the frame 103 shown in FIG. 1, a picture ratio 16:9 of a lateral size to a vertical size of the left-eye image 101 and the right-eye image 102 is reduced to 8:9 of one picture 103 having a picture ration of 16:9 and is input into one channel or one input device.

Here, when the 3D image is projected to a general projector as shown in FIG. 1, the left-eye image 101 and the right-eye image 102, together with a screen image 104, is viewed only as the images which is reduced to ½ in a picture size leftward and rightward or top and bottom, and cannot be viewed as 3D image.

Further, a technology has been proposed to separate the left-eye image 101 and the right-eye image 102; however, according to the technology, even though the left-eye image and the right-eye image are projected on a screen, the images are viewed as vertically elongated as shown in the screen image 104 of FIG. 1, and thereby not being practical. Specially, with respect to a picture size, the technology of magnifying leftward and right ward the images, leaving vertically the image as original size can not be combined simultaneously to a technology of separating the images.

In order to solve the aforementioned drawbacks, according to a prior art, an electronic division device 105 in which a separate image division and magnification circuit board is embedded is provided in a projector for 3D image to divide the left-eye image 101 and the right-eye image 102 placed in one frame 103 by using the electronic division device 105. After that, the reduced pictures are magnified leftward and rightward to an original size and the left-eye image 101 and the right-eye image 102 are projected at a time interval on a screen, as 107 a and 107 b in FIG. 1., to be viewed through the shutter-type eyeglass for 3D image 109 in which the left and right sides are opened and closed in a synchronizing manner.

However, a shutter unit, a synchronizing signal, and a receiving unit, etc., have to be provided on the shutter-type eyeglass 109, and thus the eyeglass itself is weighty and inconvenience for use and expensive, and thus the shutter-type eyeglass has not been appropriate for a large screen for multiple viewers, which is usually installed in a theater, sports café or assembly hall.

Further, since the time signal for exchanging the left-eye image and the right-eye image have to be received from the screen to the 3D image eyeglass 109 to simultaneously drive the shutters of the 3D image eyeglass, the signal is weakened to a viewer placed at a remote distance from the screen and thus the viewer can not clearly see the 3D image.

Here, a polarization wheel has been provided in front of the 3D image projector through which the left-eye image 101 and the right eye image 102 are projected at a time interval to be projected on a screen through a 3D image eyeglass 108; however, the polarization wheel configuration is complicated and the brightness of the image is reduced to ½ and further is reduced to ½ through the polarization wheel to greatly decrease a picture quality.

Further, the left-eye image 101 and the right-eye image 102 are respectively projected at a different angle and overlapped on a screen 106 by generally using two projectors, and then the left-eye image 101 and the right-eye image 102 are to be viewed on a left eye and a right eye, respectively, as a 3D image by using a polarization eyeglass 108 having the same polarization angle as the projection lens.

In summary, there has been no technology in the prior art except for a 3D image shutter eyeglass 109 manner using one projector and a polarization eyeglass manner using two projectors or two projection engines.

Here, two projectors or a projector having two optical engines has to be necessary in order to use the polarization eyeglass and further a complicated polarization wheel has to be additionally used in order to the polarization eyeglass with respect to one projector.

Accordingly, there needs a technology through which a 3D image combined one frame 103 is divided and at the same time magnified and polarized to be clearly viewed by using a general projector through a polarization eyeglass.

SUMMARY OF THE INVENTION

An aspect of the present invention is directed to a 3D image convertible projection optical system through which a left-eye image 101 and a right-eye image 102 which are reduced leftward and rightward (vertically) in a picture size of one frame 1 are magnified and at the same time divided to be projected.

The present invention relates to provide a 3D image convertible projection optical system which includes a curved surface mirror and a reflection mirror, a curved surface lens, a curved surface lens and reflection mirror, an eccentric curved surface lens, and an eccentric curved surface lens and reflection mirror.

The 3D image convertible projection optical system according to the present invention includes an optical image magnification configuration and an image division configuration.

Firstly, the 3D image convertible projection optical system according to the present invention includes: a first curved surface mirror which selects and magnifies leftward and rightward horizontally the image projected from a projector receiving a left-eye image and a right-eye image within one frame, and at the same time divides the image into two images; a second curved surface mirror which magnifies secondly leftward and rightward the left-eye image and the right-eye image separated from the first curved surface mirror, and magnified and reflected, and at the same time projects them toward a screen; and a polarization filter for polarizing the left-eye image and the right-eye image magnified through the first and second curved surface mirrors and projecting them toward a screen.

Secondly, according to the 3D image convertible optical system, a Curved surface lens a horizontal direction part of which is curved and a vertical directional part of which is flat and which magnifies only horizontally the image is provided leftward and rightward as plural in front surface of a projection lens of a general projector and further a left and right polarization plates are provided on the respective left and right curved surface lens, if necessary, a reflection mirror is connected the curved surface lens for magnifying and separating the left-eye image and the right-eye image.

Thirdly, according to the 3D image convertible projection system, a eccentric curved surface lens for magnifying the images only leftward and rightward, a horizontal direction part of which is curved and a vertical direction part of which is flat such as the curved surface lens optical system, is provided leftward and rightward as plural wherein the curvature of the eccentric curved lens are the same, and the center of the curvature is divided to form two optical axes. Here, a symmetric configuration for the eccentric curved surface lens is made based on the two optical axes to form a dual symmetric structure having an eccentric part, and further a polarization plate is connected the eccentric curved surface lens, respectively, and if necessary, a reflection mirror is connected the eccentric curved surface lens to divide the image into two optical axes.

According the present invention, a 3D image convertible projection optical system may be connected easily to a front surface of projection lens of a general projector and thus one left-eye image and right-eye image input into a general projector is divided leftward and rightward and at the same time the reduced images are magnified to a original size to be projected at different polarization angle on a screen wherein the images are combined on the screen and thus a viewer can see the 3D image through a polarization eyeglass using a general projector.

Specially, these images are as 2-4 times bright and clear as a prior 3D projector through the 3D image convertible projection optical system, instead of electronic device. Accordingly, the 3D image convertible projection optical system is cost saved and light-weighted, and further 3D image can be viewed using a polarization eyeglass without a separate electronic device, a separate complicated polarization wheel device and a separate synchronization signal in a theater, class and assembly hall.

Furthermore, the 3D image convertible projection optical system according to the present invention may be assembled or disassembled to an existing projector and thus in case where the 3D image convertible projection optical system is assembled to the projector, 3D image can be viewed and in case where the 3D image convertible projection optical system is disassembled, 2D image can be viewed using the prior projector.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a view showing the images which are varied during a 3D image transmitting procedure for 3D image broadcasting and 3D image blu-ray;

FIG. 2 is a perspective view showing a 3D image convertible projection optical system according to the present invention;

FIG. 3 is a perspective view showing a configuration of a first and second curved surface mirror according to the present invention;

FIG. 4 is a cross-sectional view showing the first and second curved surface mirror shown in FIG. 3;

FIG. 5 is a perspective view showing an exemplary embodiment of the first and second curved surface mirror according to the present invention;

FIG. 6 is a view showing a configuration of the first and second curved surface mirror according to the present invention;

FIG. 7 is a perspective view showing a non-curved surface mirror according to the present invention;

FIG. 8 a is a perspective view showing a curved surface lens according to the present invention;

FIG. 8( c) is a perspective view showing an eccentric curved surface lens which is formed symmetrically leftward and rightward by dividing the curved surface lens into two parts;

FIG. 8( d) is a perspective view showing a double axis of the eccentric curved surface lens;

FIG. 9 is a perspective view showing a left-right eccentric curved surface lens according to the present invention;

FIG. 10 is a perspective view showing an exemplary embodiment of the left-right curved surface lens according to present invention;

FIG. 11 is a perspective view showing a configuration of a curved surface according to the present invention;

FIG. 12 is a perspective view showing an exemplary embodiment of the curved surface lens according to the present invention;

FIG. 13 is a perspective view showing an optical operation of a spherical mirror according to the present invention; and

FIG. 14 is a perspective view showing an optical operation of a curved surfaced mirror according to the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Wherever possible, the same reference numerals will be used to refer to the same elements throughout the specification, and a duplicated description thereof will be omitted. It will be understood that although the terms “first”, “second”, etc. are used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element.

The 3D image convertible projection optical system according to the present invention may be applied to a projector for 2D image which receives the image that is configured by combining leftward and rightward or vertically a left-eye image and a right-eye image for 3D image in one frame and transmitted as a 2D form, and projects the image to a projection lens.

A 3D image for a general 3D image TV broadcasting or blu-ray is configured in such a manner that, as shown in FIG. 1, the left-eye image 101 and the right-eye image 102 are arranged as one image side by side or top and bottom in one frame 103.

Here, the arrangement of the image is mainly described based on side by side configuration for description convenience; however, a principle of the arrangement of the image may be applied similarly to a top and bottom configuration.

In general, a picture ratio of a lateral length to a vertical length of an image for TV or DVD may be 16:9, and further may be 2.35:1, etc., for a movie image. Here, the 3D image convertible projection system will be described based on a picture ratio of 16:9 for description convenience.

In order to convert the left-eye image 101 and the right-eye image 102 input as a 2D form into the frame 103, the following conditions are necessary.

Firstly, in one frame configuration the left-eye image 101 and the right-eye image 102 are divided into the separate left-eye image 101 and the right-eye image 102 since the left-eye image 101 and the right-eye image 102 are input at the same time into one frame 103, as shown in FIG. 1, and the left-eye image 101 has to be viewed through a left eye and the right-eye image 102 has to be viewed through a right eye, respectively.

Secondly, the left-eye image 101 and the right-eye image 102, which are picture size-reduced in one frame 103 as shown in FIG. 1, are magnified originally again as the screen image 106, 107 a and 107 b as shown in FIG. 1.

Thirdly, with respect to a magnification rate, in case where the left-eye image and the right-eye image are arranged side by side, the images are magnified only horizontally to 1.5-2.5 times and in case where the left-eye image and the right-eye image are arranged top and bottom, the images are magnified only vertically to 1.5-2.5 times, since the left-eye image 101 and the right-eye image 102 are size-reduced such as the screen 104 image as shown in FIG. 1. Here, 1.5 times picture is effective when the input picture ratio is 2.35:1, and 2.5 times picture is effective when the input picture ratio is 4:3.

Fourth, the left-eye image 101 and the right-eye image 102, which are divided and magnified, are divided at different polarization angle such as the screen 106 image as shown in FIG. 1, and then combined on one screen a picture ratio of which 16:9-2.35:1. The reason is that even if the left-eye image 101 and the right-eye image 102 are overlapped on the screen 106, the left-eye image 101 and the right-eye image 102 can be viewed separately to a left eye and a right eye, respectively, through a polarization eyeglass thereby the 3D image being viewed.

Fifth, the division, magnification, polarization and projection operations are performed simultaneously in one optical system since in case where the division and magnification are performed separately, brightness may be lost and resolution may be decreased, and in special when a polarization and projection are not performed simultaneously, a polarization degree is not kept to unable 3D picture to be formed, and further when the 3D image convertible projection optical system is arranged in a separate case 1 as shown in FIGS. 2 and 4, a volume is large and weight is heavy, and thereby being difficult to be assembled to a general projector.

Hereinafter, exemplary embodiment of the present invention will be described in detail with reference to the drawings.

The 3D image convertible projection optical system may be applied to a projection lens 300 of a general projector 200 to determine a projection distance. Here, a focal point distance of a standard projection lens of the projector 200 may be 30 mm or less, and the description of the 3D image convertible projection optical system will be made based on the focal point distance of 30 mm of the standard projection lens. In case where the projection lens having different focal point distances, the principle may be applied similarly thereto.

Embodiment 1

FIGS. 3 and 4 show a 3D image convertible projection optical system according to the present invention including a first and second curved surface mirrors 2, 3 wherein a left and right first curved surface mirrors 2 a, 2 b, which are symmetrically arranged at an inclination angle of 45° based on a center line of the projection lens 300, are provided in front part of the projection lens, and wherein a left and right second curved surface mirrors 3 a, 3 b, which are symmetrically arranged at the same inclination angle as the left and right first curved surface mirrors 2 a, 2 b to project the image toward a screen, are provided on a left and right sides of the respective left and right first curved surface mirrors 2 a, 2 b, and wherein a polarization plates 4, which are arranged in a parallel direction to the projection lens and have different left and right polarization angles, are provided in front part of the left and right first curved surface mirrors 2 a, 2 b. Here, the left-eye image and right-eye image for 3D image combined in one frame are divided and magnified and then polarized at the polarization angle through the aforementioned configuration. After that, the divided left-eye image and the right-eye image are projected in an overlapping manner on a screen.

Further, the curvature rate of the curved surface is determined such that a ratio of top and bottom picture size to left and right picture size of the left and right first curved surface mirrors 2 a, 2 b and the left and right second curved surface mirrors 3 a, 3 b is 1.5:2.5.

Meanwhile, a curvature form of the left and right first curved surface mirrors 2 a, 2 b and the left and right second curved surface mirrors 3 a, 3 b is non-spherical surface.

Furthermore, any one of the left and right first curved surface mirrors 2 a, 2 b and the left and right second curved surface mirrors 3 a, 3 b is plain surface, and a magnification rate of the rest curved surface mirrors is 1.5-2.5 based on top and bottom picture size to left and right picture size.

The aforementioned configuration is arranged on a separate case so that it may be combined to an existing projector and separated from the existing projector.

The aforementioned configuration may be connected to a projection lens of a projector.

In more detailed description, as shown in FIGS. 3 and 4, two left and right first curved surface mirrors 2 are arranged symmetrically at an inclination degree of 45° based on a centre of an inner rear surface of a case 1 in an opposite direction horizontally and leftward and rightward, and two left and right second curved surface mirrors 3 are arranged symmetrically at an inclination degree of 45° in front part of the left and right first curved surface mirrors 2, respectively.

In much more detailed description, in order that the image projected from a projector for 2D image which receives the image transmitted as one image formed by reducing a left-eye image and a right-eye image for 3D image to a ½ size and arranged in one frame and projects to a projector lens, are divided leftward and rightward and the reduced and divided images are magnified to an original size, a left first curved surface mirror 2 a is arranged at an left inclination angle of 45° and a right first curved surface mirror 2 b is arranged at a right inclination angle of 45°, as shown in FIGS. 3 and 4, based on a vertex wherein the left first curved surface mirror and the right first curved surface mirror are arranged linear symmetrically to form a triangle form having the vertex on which a center line c of the projection lens 300 is arranged. Further, the left second curved surface mirror 3 a and the right second curved surface mirror 3 b are arranged at a left inclination angle of 45° and a right inclination angle of 45° respectively, in parallel to the left curved surface mirror 2 a and the right first curved surface mirror 2 b.

In addition, a polarization plate 4 having different left and right polarization angles is provided in front locations of the left second curved surface mirror 3 a and the right second curved surface mirror 3 b, in parallel to the projection lens 300, and further these elements may be provided in one case 1.

As a result, the image is divided into two parts by the left first curved surface mirror 2 a and the right first curved surface mirror 2 b on the center c of the projection lens 300, as shown in FIG. 4, to be reflected and refracted leftward and rightward and then reflected and refracted by the left second curved surface mirror 3 a and the right second curved surface mirror 3 b toward a screen to be projected through the left and right projection plates 4 which are arranged in parallel to the projection lens.

Here, a horizontal part of the first and second curved surface mirrors 2, 3 is configured as a curved surface A having a curvature R and a vertical part B thereof is configured as a plain surface, that is, only one part of the first and second curved surface mirror is curved.

Meanwhile, the curvature R of the first and second curved surface mirrors 2, 3 is as follows.

A focal point distance of a standard projection lens of a general projector is 30 mm. As a result, according to the present invention, the lateral picture sizes of the divided left-eye image 101 and right-eye image 102 are magnified to 1.5-2.5 times and the top and bottom images are not magnified.

For reference, a magnification rate formula for a spherical mirror, as shown in FIG. 13, a focal point distance of a spherical mirror having a curvature R, F=R/2. In addition, S1 is a first focal point distance of the spherical mirror and S2 is a second focal point distance of the spherical mirror wherein a relation between S1 and S2 is 1/f=1/S1+1/S2.

Furthermore, the magnification rate, M=S2/S1 wherein the relation between S1 and S2 is 1/f=1/S1+1/S2. The magnification rate 2 equals to 1.414² due to area comparison.

Accordingly, when a focal point distance of a projection lens to which the 3D image convertible projection optical system is attached is 30 mm, a focal point distance of a vertical picture is not varied, that is, the focal point distance is 30 mm, a focal point distance of a horizontal picture is about 21.5 mm (30 mm/1.442)

In a similar principle, a magnification rate 1.5 times=1.22² and 2.5 times=1.58², and thus a focal point distance of the first and second curved surface mirrors 2, 3, F is within 18.9-24.5 mm, corresponding to the 1.5-2.5 times.

Here, a relation between the focal point distance F and the curvature R is F=R/2 and thus the curvature of the first and second curved surface mirrors 2, 3 is within 18.9-24.5 mm. Additionally, the curvature R is divided through the first curved surface mirror 2 and the second curved surface mirror 3 to be 75.6-98 mm.

That is, only a horizontal magnification rate of a summation of the curvatures R of the first and second curved surface mirrors 2, 3 is 1.5-2.5 times.

Meanwhile, polarization plates 4 may be provided on a front surface of the left and right second curved surface mirror 3 and further an eccentric prism 5 may be provided on a front surface thereof, if necessary.

The eccentric prism 5 having a relative small apical angle, as shown in FIGS. 4 and 5, is provided mainly for compensating the projection direction. Here, since a chromatic aberration may occur to the eccentric prism 5, a glass element having a different refraction rate may be attached to the eccentric prism 5 for eliminating the chromatic aberration.

Through this configuration of the 3D image convertible projection optical system according to the present invention, the left-eye image 101 and the right eye-image 102 input into one frame 103 with respect to a general projector 200, as shown in FIG. 1, are divided leftward and rightward through the left and right first curved surface mirrors 2, and then the horizontal images of the left-eye image and right-eye image are magnified to 1.5-2.5 times through the second curved surface mirrors 3 to be projected toward a screen. After that, the images are polarized through the left and right polarization plates 4 provided on a front surface of the left and right second curved surface mirrors 3 to be projected on the screen.

That is, the left-eye image 101 and the right-eye image 102 are divided at the same time and magnified leftward and rightward, and then polarized and separated through one optical system to be project on a screen in an overlapping manner.

At this time, an eccentric prism 5 may be further provided to adjust a left and right interval of the left-eye image 101 and the right-eye image 102.

Embodiment 2

As shown in FIG. 5, according to the present embodiment of the present invention, a 3D image convertible projection optical system is configured in such a manner that one of the first curved surface mirror 2 and the second curved surface mirror 3 is a plain surface and the other curved surface mirror is curved wherein only the horizontal magnification rate of the curved surface mirror is 1.5-2.5 times.

Here, a principle and operation of the configuration is the same as shown in FIGS. 3 and 4. For example, a curvature R of one of the first curved surface mirror 2 and the second curved surface mirror 3 is 37.8-49 mm of two times long as that of the first and second curved surface mirrors 2, 3.

In this case, a vertical picture magnification rate becomes 0 and a horizontal picture rate becomes 1.5-2.5 times, comparing to a focal point distance of a projection lens of a general projector 200.

Therefore, according to the 3D image convertible projection optical system, as similar to the first embodiment, the left-eye image 101 and the right-eye image 102 are divided at the same time and magnified leftward and rightward, and then polarized and separated through one optical system to be project on a screen in an overlapping manner.

Embodiment 3

Differently from a configuration of the lens of the first and second curved surface mirrors 2, 3 as described in embodiments 1 and 2, according to the present embodiment, there is no chromatic aberration and brightness decreasing is minimized and a volume of the system is minimized.

Meanwhile, with respect to a horizontal magnification rate, the chromatic aberration such as a trapezoid form leftward and rightward may occur in the projected images. Here, in order to compensate the chromatic aberration, as shown in FIG. 7, a plurality of curvatures are overlapped on one curved surface A to form a non-spherical surface.

That is, in case of a main curvature R being 150 R(mm), as going to a surrounding, R1=160R, and R2=170R and as a result a non-spherical surface is formed to compensate the chromatic aberration. According to the present embodiment, an enlarged chromatic aberration may be eliminated in a curved surface mirror.

Embodiment 4

According to the present embodiment, a 3D image convertible projection optical system is configured in such a manner that any one of the configurations as set forth in the embodiments 1-3 is provided in a separate case 1, as shown in FIG. 4, and is assembled or disassembled to a general projector 200, as shown in FIG. 2. Further, the 3D image convertible projection optical system may be connected to a general projector itself 2 without being restructured. That is, any one of 3D image convertible projection optical systems as set forth in embodiments 1-3 may be connected to a projection lens of a general projector 200.

Embodiment 5

According to the present embodiment, a 3D image convertible projection optical system is configured in such a manner that a curved surface lens a horizontal part of which is curved and a vertical part of which is straight-line is provided in a front surface of a projection lens of a projector which receives the left-eye image 101 and the right eye-image 102 in one frame 103 and projects, as shown in FIG. 9.

As shown in FIGS. 8( a), 8(b), and 8(c), the curved surface mirror is provided, a horizontal part of which is curved and a vertical part of which is straight-line wherein a center c of the curved surface lens 6, as shown in FIG. 8( a), is divided vertically as indicated line C-C to form a left eccentric curved surface lens 7 a and a right eccentric curved surface lens 7 b and further, as shown in FIG. 8( c) the left surface and right surface of the left eccentric curved surface lens 7 a and the right eccentric curved surface lens 7 b are exchanged to arrange symmetrically the left eccentric curved surface lens 7 a and the right eccentric curved surface lens 7 b wherein the outer surface B is placed on a center of the curved surface mirror and the center part C is placed outward.

The left and right eccentric curved surface lens 7 a, 7 b have same curvature R and thus, as shown in FIG. 8( d), one image formed by one optical axis before division is divided by two optical axes to separate the left-eye image 101 and the right-eye image 102.

Here, as shown in FIG. 9, a left polarization plate 4 and a right polarization plate 4 are provided on a front surface of the respective eccentric curved surface lens 7 a, 7 b to magnify and separate the left-eye image 101 and the right-eye image 102 projected from a projector.

At this time, a left and right magnification rate of the left and right eccentric curved surface lens 7 a, 7 b is 1.5-2.5 times as a vertical picture magnification rate. A formula for the magnification rate is as follows.

As shown in FIG. 14, a formula for a focal point distance a lens, F=(1−ND)(1/r1+1/r1) wherein ND is a refraction rate of lens glass element, assuming that a standard refraction rate is 1.50, r is a curvature of a lens front surface, and r1 is a refraction rate of a rear surface of a lens.

Here, according to the formula for a focal point distance, as shown in FIG. 9( a), based on 30 mm of a focal point distance for a projection lens of a general projector 200, the focal point distance F is 47-103 mm.

In this case, a horizontal magnification rate of the left and right eccentric curved surface lens 7 a, 7 b is 1.5-2.5 times and a vertical magnification rate is 0 and thereby forming a lateral magnification lens.

The lens having one curvature R is divided into two optical axes through the optical system configured as set forth above and thus the lens having same performance and two eccentric axes can be obtained to eliminate errors of left lens and right lens.

Embodiment 6

According to the present embodiment, as shown in FIG. 10, the left and right reflection mirrors 9 are provided in a front surface of the left and right eccentric curved surfaces 7 a, 7 b.

Embodiment 7

According to the present embodiment, one configuration of embodiments 5 and 6 is provided in a separate case 1 to be assembled or disassembled to a general projector 200, or the configuration is assembled to a general projector. Here, an interval of the divided image of the left-eye image 101 and the right-eye image 102 is adjusted by a reflection plate 9 and a polarization plate 4 on a screen and the image polarized by the polarization plate 4 is projected on one screen.

Embodiment 8

According to the present embodiment, as shown in FIG. 11, a curved surface lens is configured in such a manner that a horizontal part of the lens is curved and a vertical part thereof is flat surface. The curved surface lens are provided as a plural leftward and rightward and further two polarization plates 4 are provided to the left and right curved surface lens to magnify and divide the left-eye image and the right-eye image which are projected from a projector.

That is, according to the present embodiment, the curved surface lens 6 and the polarization plate 4 are provided wherein a horizontal part of the curved surface lens 6 is curved having a curvature R and a vertical part thereon is flat, or the horizontal part and the vertical part of the curved surface lens are all curved in which a rate of a focal point distance of the horizontal part b and the vertical part a is 1.5-2.5 to 1.

That is, in case where the horizontal part and the vertical part of the lens are curved having a curvature R in order to reduce a lens aberration, a magnification rate of a horizontal surface to a vertical surface has to be 1.5-2.5 times.

Meanwhile, as shown in FIG. 12, a eccentric prism 5 is provided leftward and rightward in front surface of the left curved surface lens 6 a and the right curved surface lens 6 b, respectively, and a reflection mirror 9 is provided on a left and right sides of the left curved surface lens 6 a and the right curved surface lens 6 b, respectively.

According to the present embodiment, as similar to the embodiment 1, the left-eye image 101 and the right-eye image 102 are divided at the same time and magnified horizontally through one optical system, and polarized and separated to be projected on a screen in an overlapping manner.

Embodiment 9

According to the present embodiment, one configuration of embodiments 5 and 6 is provided in a separate case 1 to be assembled or disassembled to a general projector 200, or the configuration is assembled to a general projector.

Accordingly, the configuration as set forth in the above embodiments are configured in an optical system, instead of electronic device, and the 3D image convertible optical system is provided in a separate case 1 to be assembled or disassembled to an outside of a projection part of a general projector 200 wherein the left-eye image 101 and the right-eye image 102 which are arranged side by side in one frame 103 are magnified only horizontally to 1.5-2.5 times and further in case where the left-eye image 101 and the right-eye image 102 are arranged in a top and bottom manner, they are magnified vertically to 1.5-2.5 times, similar to the arrangement side by side.

Accordingly, the left-eye image 101 and the right-eye image 102, which are arranged side by side, or in a top and bottom manner, are divided into two images, are magnified horizontally or vertically depending on choice, to 1.5-2.5 times.

While the invention has been shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the scope of the invention is defined not by the detailed description of the invention but by the appended claims, and all differences within the scope will be construed as being included in the present invention. 

1. A 3D image convertible projection optical system comprising: a left-eye image (101) and a right-eye image (102) for 3D image that are transmitted at the same time from one frame (103) among the images projected from a projector; two first curved surface mirrors (2) for dividing and at the same time magnifying the left-eye image (101) and right-eye image (102), which are arranged symmetrically each other and one directional part of which is curved and the other directional part of which is flat; two second curved surface mirrors (3) which are arranged at an inclination angle for reflecting the left-eye image (101) and the right-eye image (102) toward a screen, correspondingly to the two first curved surface mirrors (2); and a polarization plate (4) provided respectively on the second curved surface mirrors (3).
 2. The 3D image convertible projection optical system of claim 1, wherein the first and second curved surface mirrors having a function of magnifying the left-eye image and right-eye image 1.5-2.5 times in one of a horizontal direction and a vertical direction.
 3. The 3D image convertible projection optical system of claim 1, wherein a curvature form of the first curved surface mirrors and the second curved surface mirrors is non-curved surface.
 4. The 3D image convertible projection optical system of claim 1, wherein at least one of the first curved surface mirrors and the second curved surface mirrors is a flat mirror and a magnification rate of the rest curved surface mirrors is 1.5-2.5 times.
 5. The 3D image convertible projection optical system of claim 1, wherein it is fabricated in a separate case and is assembled or disassembled to a general projector.
 6. The 3D image convertible projection optical system of claim 1, wherein it is connected to a projection lens of a general projector.
 7. A 3D convertible projection optical system comprising: a projector for receiving the left-eye image (101) and the right-eye image (102) in one frame (103) and then projects the left-eye image (101) and the right-eye image (102) toward a projection lens; a curved surface lens (6) provided in front part of the projection lens of the projector, one directional part of which is curved and the other directional part of which is flat; and a polarization plate provided in the curved surface lens (6).
 8. The 3D convertible projection optical system of claim 7, wherein a prism is provided in a front surface of the respective curved surface lens (6).
 9. The 3D convertible projection optical system of claim 7, wherein a reflection mirror is provided in the curved surface lens (6).
 10. The 3D convertible projection optical system of claim 7, wherein a magnification rate of the curved surface lens (6) is 1.5-2.5 times.
 11. The 3D convertible projection optical system of claim 7, wherein it is fabricated in a separate case and is assembled or disassembled to a general projector.
 12. The 3D image convertible projection optical system of anyone of claim 1, wherein it is connected to a projector.
 13. A 3D image convertible projection optical system comprising: a projector for receiving the left-eye image (101) and the right-eye image (102) in one frame (103) and then projects the left-eye image (101) and the right-eye image (102) toward a projection lens; a curved surface lens attached to a projection lens of the projector; and a polarization plate provided on a left and right eccentric curved surface eccentric lens (7 a, 7 b) having two optical axes, which are configured symmetrically by dividing a center of the curved surface lens into two parts of a left eccentric curved surface lens (7 a) and a right eccentric curved surface lens (7 b) and exchanging a left eccentric curved surface lens (7 a) and a right eccentric curved surface lens (7 b).
 14. The 3D image convertible projection optical system of claim 13, wherein a prism is provided in the left and right eccentric curved surface lens (7 a, 7 b).
 15. The 3D image convertible projection optical system of claim 13, wherein a left and right reflection mirrors are provided in the left and right eccentric curved surface lens (7 a, 7 b).
 16. The 3D image convertible projection optical system of claim 13, wherein the respective magnification rate of the left and right eccentric curved surface lens (7 a, 7 b) is 1.5-2.5 times.
 17. The 3D image convertible projection optical system of claim 13, wherein it is fabricated in a separate case and is assembled or disassembled to a general projector.
 18. The 3D image convertible projection optical system of claim 13, wherein it is connected to a projector. 